<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>offset-distance interpolation</title>
    <link rel="author" title="Eric Willigers" href="mailto:ericwilligers@chromium.org">
    <link rel="help" href="https://drafts.fxtf.org/motion-1/#offset-distance-property">
    <meta name="assert" content="offset-distance supports animation.">
    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
    <script src="/css/support/interpolation-testcommon.js"></script>
  </head>
  <style>
    .parent {
      offset-path: ray(30deg closest-side);
    }
    .target {
      offset-path: ray(10deg closest-side);
    }
  </style>
  <body>
    <script>
      'use strict';

      test_no_interpolation({
        property: 'offset-path',
        from: "path('M 0 0 L 100 100 M 100 200 L 200 200 Z L 200 100 Z')",
        to: "ray(0deg closest-side)",
      });

      test_no_interpolation({
        property: 'offset-path',
        from: "ray(0deg closest-corner)",
        to: "none",
      });

      // Neutral keyframes use the inline style.
      test_interpolation({
        property: 'offset-path',
        from: neutralKeyframe,
        to: 'ray(20deg closest-side)',
      }, [
        {at: -0.3, expect: 'ray(7deg closest-side)'},
        {at: 0, expect: 'ray(10deg closest-side)'},
        {at: 0.3, expect: 'ray(13deg closest-side)'},
        {at: 0.6, expect: 'ray(16deg closest-side)'},
        {at: 1, expect: 'ray(20deg closest-side)'},
        {at: 1.5, expect: 'ray(25deg closest-side)'},
      ]);

      // No interpolation to a ray from the initial value 'none'.
      test_no_interpolation({
        property: 'offset-path',
        from: 'initial',
        to: 'ray(20deg closest-side)',
      });

      // 'inherit' keyframes use the parent style.
      test_interpolation({
        property: 'offset-path',
        from: 'inherit',
        to: 'ray(20deg closest-side)',
      }, [
        {at: -0.3, expect: 'ray(33deg closest-side)'},
        {at: 0, expect: 'ray(30deg closest-side)'},
        {at: 0.3, expect: 'ray(27deg closest-side)'},
        {at: 0.6, expect: 'ray(24deg closest-side)'},
        {at: 1, expect: 'ray(20deg closest-side)'},
        {at: 1.5, expect: 'ray(15deg closest-side)'},
      ]);

      // No interpolation to a ray from the initial value 'none'.
      test_no_interpolation({
        property: 'offset-path',
        from: 'unset',
        to: 'ray(20deg closest-side)',
      });

      // No interpolation to a ray from the initial value 'none'.
      test_no_interpolation({
        property: 'offset-path',
        from: 'none',
        to: 'ray(20deg closest-side)',
      });

      // Interpolation between rays.
      test_interpolation({
        property: 'offset-path',
        from: 'ray(10deg sides contain)',
        to: 'ray(50deg sides contain)'
      }, [
        {at: -1, expect: 'ray(-30deg sides contain)'},
        {at: 0, expect: 'ray(10deg sides contain)'},
        {at: 0.125, expect: 'ray(15deg sides contain)'},
        {at: 0.875, expect: 'ray(45deg sides contain)'},
        {at: 1, expect: 'ray(50deg sides contain)'},
        {at: 2, expect: 'ray(90deg sides contain)'},
      ]);

      test_interpolation({
        property: 'offset-path',
        from: 'ray(-10deg farthest-corner)',
        to: 'ray(-50deg farthest-corner)'
      }, [
        {at: -1, expect: 'ray(30deg farthest-corner)'},
        {at: 0, expect: 'ray(-10deg farthest-corner)'},
        {at: 0.125, expect: 'ray(-15deg farthest-corner)'},
        {at: 0.875, expect: 'ray(-45deg farthest-corner)'},
        {at: 1, expect: 'ray(-50deg farthest-corner)'},
        {at: 2, expect: 'ray(-90deg farthest-corner)'},
      ]);

      // No interpolation between different sizes and/or different containment.
      test_no_interpolation({
        property: 'offset-path',
        from: 'ray(200deg farthest-side)',
        to: 'ray(300deg sides)'
      });
      test_no_interpolation({
        property: 'offset-path',
        from: 'ray(200deg sides contain)',
        to: 'ray(300deg sides)'
      });
      test_no_interpolation({
        property: 'offset-path',
        from: 'ray(200deg farthest-side contain)',
        to: 'ray(300deg sides)'
      });
    </script>
  </body>
</html>
